Ribbon feed mechanism for business machines and the like



June 12, 1962 P. FRECHETTE, JR., ETAL 3,033,532

RIBBON FEED MECHANISM FOR BUSINESS MACHINES AND THE LIKE 3 Sheets-Sheet 1 Filed Dec.

U A JHNWH mmm m R E E E A N 0 O H R TC C 0 NE .E mm D W R A IRRUO HN mama LR R m June 12, 1962 L. P. FRECHETTE, JR., ETAL. 3,038,582

RIBBON FEED MECHANISM FOR BUSINESS MACHINES AND THE LIKE Filed Dec. 23, 1960 s Sheets-Sheet 2 INVENTORS LEO I? FRECHETTE JR. ROBERT E. McGRATI-l ARTHUR L.CHARBONEAU PEYNOLD E. WHEELER ATTORNEYS June 12, 1962 L. P. FRECHETTE, JR, ETAL 3 Sheets-Sheet 3 Filed Dec. 23, 1960 V Q 3 0 w 4 6 R v 4/7 X H Z/K/ .M\\ l 3 5 M w E Q 0 a 4 5 4 I P w m Fig. 4

U m R M mm a w T E SE H E RHGAW N OCCH R T% o m D W V .TRL .A mwm OBTY EORE LRAR B l Sates 3,d38,582 Fatented dune 12, 1962 3,038,582 RIBBQN FEED MECHANISM FOR BUSINESS MAQHINES AND TI-m LIKE Leo I. Frechette, In, West Hartford, Conn, Robert E.

MeG-rath, Feeding Hills, Mass, and Arthur L. Charboneau, West Hartford, and Reynold E. Wheeler, Farmington, (101111., assignors to Royal McBee Corporation, Port Chester, N.Y., a corporation of New York Filed Dec. 23, 1960, Ser. No. 77,887 14 Claims. (Cl. 197-160) This invention relates to a ribbon feed mechanism for business machines and the like, and more particularly relates to power operated devices for incrementally and reversibly feeding a typewriter printing ribbon.

In many conventional typewriters the spring barrel is connected so as to not only incrementally drive the carriage but also to rotatably drive the ribbon spools and/ or to reverse the ribbon feed mechanism. This type of ribbon feed mechanism is undesirable in electric typewriters where high speed typing occurs. If during such high speed operations the spring barrel is overloaded by having to rapidly drive the ribbon feed mechanism as well as the record supporting carriage then it may not be able to impart an intermittent letter feeding movement to the carriage which is fast enough to accommodate the relatively high printing speeds. In that there are several readily available power operated elements in an electric typewriter it is desirable to use one or more of these elements to incrementally drive the ribbon feed device and/or to reverse the ribbon feed drive means.

One object of the instant invention is to provide an improved power operated device for incrementally feeding the printing ribbon of a business machine.

Another object of the invention is to provide an improved power operated device for reversing the ribbon feed mechanism of a business machine.

Another object of the invention is to provide a novel power operated ribbon feed reversing mechanism for business machines whereby the reversing mechanism is cam operated in one direction and spring operated in the opposite direction.

Another object of the instant invention is to provide a novel power operated device for incrementally feeding the printing ribbon of an electric typewriter or the like whereby a clutch is operatively connected between the typewriter power roll and ribbon spool drive means.

Another object of the instant invention is to provide a novel power operated device for incrementally feeding the printing ribbon of an electric typewriter or the like whereby a clutch is operatively connected between the typewriter power and spool drive means, said clutch being controlled by an escapement mechanism that is cyclically operated by the typewriter universal bail.

Another object of the instant invention is to provide a power operated reversing arrangement for the ribbon feed drive means of an electric typewriter whereby the said reversing arrangement is biased to a normal position wherein the printing ribbon may be fed in one longitudinal direction and whereby the said reversing arrangement may be power driven to and then latched in an alternate position wherein the printing ribbon may be fed in the pposite longitudinal direction.

Another object of the invention is to provide a novel power operated ribbon feed reversing control mechanism for an electric typewriter whereby the typewriter power roll is intermittently coupled to said mechanism under the control of the ribbon feed sensing devices of said typewriter.

Another object of the invention is to provide a novel power operated mechanism for the ribbon feed drive means of an electric typewriter whereby a wrap spring clutch is operatively disposed between the typewriter power roll and ribbon spool drive means, said wrap spring clutch being controlled by the cyclic operation of a universal bail assembly.

A further object of the invention is to provide a novel power operated reversing mechanism for the ribbon feed drive means of an electric typewriter whereby a wrap spring clutch is operatively disposed between the typewriter power roll and the ribbon drive reverse means, said wrap spring clutch being controlled by the ribbon reverse sensing linkage of the typewriter.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a perspective view of the instant power operated mechanisms for incrementally actuating and for reversing the typewriter ribbon drive means.

FIGURE 2 is a front elevational view of the apparatus of FIGURE 1.

FIGURE 3 is a fragmentary view in partial section and shows the construction of a wrap spring clutch arrangement which is adapted to operatively couple the type writer power roll to the ribbon drive means.

FIGURE 4 is a partial side elevational view of the means for controlling the operation of the wrap spring clutch of FIGURE 3.

FIGURE 5 is a perspective view illustrating the power operated ribbon drive reversing cam.

FIGURE 6 is a side elevational view in partial section and shows the control linkage for another wrap spring clutch arrangement which is adapted to operatively couple the typewriter power roll with the ribbon drive reversing means.

The conventional structure which comprises the mechanical environment for the instant invention will be described first. Referring to FIGURES l and 2 there is shown a cooperating pair of ribbon spools 10 and 11 that are operatively mounted at the respective upper ends of a pair of vertically disposed shafts 12 and 13. The spools 10 and 11 are adapted to carry a printing ribbon R in the usual manner so that said ribbon may be longitudinally fed :back and forth in front of the printing Zone or point of the machine. Shafts 12 and 13 are rotatably mounted in the machine frame 14 by any suitable means which may include the fixed frame brackets 15 and 16 and are provided at their respective lower ends with bevel gears 17 and 20. Drive means are provided for rotating the ribbon spool shafts, such means including an axially movable drive shaft 21 which is rotatably supported in the machine frame, as by said frame brackets, and which has fixed thereon a pair of axially spaced bevel gears 22 and 23 that are adapted to alternately mesh with said gears 17 and 20 respectively in response to an axial shifting movement of said drive shaft 21.

Arranged for cooperation with said ribbon spools are a pair of ribbon feed sensing devices which are operated when a reversal of the ribbon feed direction should be made, such means including a pair of vertically disposed control levers 25 and 26 that are pivotally mounted on the machine frame as by studs 27 and 30. The control levers are provided at their upper ends with bent oif arms 31 and 32 which are respectively disposed adjacent the lower flanges of said ribbon spools 10 and 11, said levers also being spring biased to normal clockwise positions, FIGURE 1, by means of springs 33 and 34 respectively.

As will be apparent the rotational movement of shaft 21 serves to longitudinally feed the printing ribbon while the axial displacement of shaft 21 serves to reverse the 3 direction of longitudinal feed of the ribbon as will be more fully described below. The construction and operation of the above described apparatus is more or less conventional in nature and need not be further discussed in detail here.

In accordance with the present invention, shaft 21 is axially biased to a normal left hand position, FIGURE 2, by means of a spring 36 that is operatively disposed between the bevel gear 22 and the adjacent end of bracket 15. Under these conditions the bevel gears 20 and 23 are normally engaged and the spool 11 may be incrementally driven. The shaft 21 is adapted to be displaced to the right, FIGURES l and 2, to a latched position wherein the bevel gears 17 and 22 will be operatively engaged so that the spool may be incrementally driven. The detenting means to retain the shaft 21 in its latched or right hand position against the action of spring 36 comprises a collar 37 fixed to said shaft and a cooperating depending finger 38 formed on the lower end of the control lever 26. The depending finger 38 is normally biased into engagement with the cylindrical periphery of the collar 37 as indicated in FIGURES 1 and 2; however, when shaft 21 is axially displaced to the right the spring 34 will displace the control lever finger 38 towards the shaft 21 so the right hand edge, FIGURE 2, of said finger moves into detenting relation with respect to the adjacent left hand radial face of collar 37. Subsequently when the ribbon has been payed off of spool 11 the control lever 26 will be displaced in a counter clockwise direction, FIGURE 1, by the associated spool ear 35 so as to move finger 38 out of detenting engagement with the collar 37 and thus permit the spring 36 to displace the shaft 21 to its normal FIGURE 1 position so as to condition the drive arrangement so that the ribbon is fed back onto spool 11.

The instant invention provides a power operated ribbon feed mechanism for incrementally rotating the drive shaft 21 and another power operated control or ribbon feed reversing mechanism for axially shifting the shaft 21 to its right hand position. These power operated mechanisms each include a wrap spring clutch through which the related mechanism may be operatively coupled to the power roll of the typewriter. The clockwise moving power roll 40 shown in the drawings may be rotatably supported and driven by any suitable means. The means for rotatably connecting the shaft 21 to the power roll comprises a gear 41 which is fixedly secured to the end of shaft 21 and which meshes with an axially elongated gear 42. A toothed escapement wheel 43 is disposed coaxially adjacent gear 42, the wheel and gear being rotatably mounted on the reduced end 44, FIGURE 3, of the power roll shaft 45 and being respectively rotatably secured to the opposite ends of wrap spring 46, said wrap spring comprising a clutch means between the power roll and the spool drive means. The clutch wrap spring coil diameter is normally slightly less than the diameter of the reduced end 44 of the power roll shaft and hence the wrap spring tends to rotate the load driving gear 42 and the wheel 43 in counter clockwise and clockwise directions respectively so that the wrap spring coils are always attempting to operatively grip the outer cylindrical surface of the said reduced shaft end 44. A pallet 47 is rotatably mounted on the machine frame by means of a suitable stud 48 and has formed at its lower end two teeth 50 and 51 which are adapted to alternately cooperate with the successive teeth 52 of the escapement wheel 43 so as to permit gear 42 to incrementally rotate, the mode of cooperation here being similar to that in any conventional type of escapement mechanism. Pallet 47 is lightly biased in a counter clockwise direction by means of a spring 53, FIGURE 4, and is articulately connected to a link 54 which is operatively connected so as to be actuated by the operation of a conventional type universal bail assembly 55, the latter being cyclically operated in the usual manner each time a typing operation occurs. In the normal condition of the parts, as illustrated in FIGURES l, 2 and 4, the pallet tooth 50 prevents the clockwise movement of both the wheel 43 and the attached right end of Wrap spring 46 and thus releasably retains the clutch wrap spring 46 in an opened or disengaged condition.

In operation each time one of the type bars of the machine partakes of a printing stroke the pallet 47, through link 54 and bail assembly 55, will be oscillated through one cycle. This cycle will permit the wheel 43 to rotatably advance in a clockwise direction, FIGURE 4, a distance equivalent to one tooth on said wheel. During the initial part of this advance the wrap spring 46 will be free to twist itself into its engaged condition and in that gear 42 will thereby be operatively coupled to the power roll shaft, the drive shaft 21 will be driven through gear 41 so as to rotate the ribbon spool 11, spool 10 being free to pay out the printing ribbon Wound thereon. After the spool 11 has been driven by the power roll through a relatively short arcuate distance the pallet tooth 50 will intercept the next one of the wheel teeth 52 thereby causing the wrap spring 46 to be moved to its disengaged condition. Thus during each successive printing operation of the typewriter the ribbon feed drive shaft 21 is momentarily coupled to the rotating power roll 40 so as to incrementally feed the printing ribbon. Between the ribbon feed stepping actions if any random counter clockwise movement, FIGURES l and 4, of gear 42 occurs which allows engagement of the Wrap spring clutch, such engagement will merely serve to slightly rotate the gear 42 in a clockwise direction which in turn will immediately disengage the clutch. Thus the rotating power roll normally assists in maintaining the wrap spring clutch in a disengaged condition.

When most of the printing ribbon has been wound onto the spool 11 the shaft 21 must be axially displaced to its latched or right hand position, FIGURE 1, against the action of spring 36 so as to reverse the direction of ribbon feed. The power operated means for accomplishing this comprises a ribbon feed reversing control bail 56, FIGURES 1 and 2, having vertical leg portions that are mounted on the shaft 21 between the gear 41 and the bevel gear 22. The central body portion of bail 56 is formed with an elongated slot 57 into which extends a detenting tab 60 which is formed on the adjacent bracket 15 or on any other suitable part of the machine frame. In this way the bail 56 is substantially axially fixed with respect to the shaft 21 and hence is capable of axially shifting the same but yet will accommodate the rotational movement of said shaft 21. The lower end of the depending bail leg portion 61 is adapted to laterally engage the radial face of the helical camming surface 62 of a cam 63, FIGURES 1, 2 and 5, that is rotatably mounted on the power roll shaft 45. A clutch wrap spring 64 is mounted on the power roll shaft 45 and has one end 65, FIGURE 6, secured in a radially disposed hole 66 formed in the cam 63 while the other spring end 67 is radially disposed and normally overlies a bent off ear 70 formed on the depending tooth 71 of a pallet 72 that is integrally formed at the lower end of said control lever 25. The radial end 67 of the wrap spring 64 together with the bent off ears 70 and 73 of the pallet teeth 71 and 74 operatively define a conventional type escapement device which in operation is similar in effect to a one revolution clutch in that a 360 degree rotation of the cam 63 is permitted in response to each cyclic oscillation of the pallet 72. The clutch Wrap spring 64 is nominally smaller in coil diameter than the cylindrical surface of the power roll shaft 45 and hence tends to move into an engaged condition wherein it circumferentially grips said surface of shaft 45. The bent-off car 70 however normally maintains the clutch wrap spring 64 in a disengaged condition. Any random counter clockwise movement, FIGURE 1, of cam 63 which moves the wrap spring 64 to its engaged condition will immediately cause a slight clockwise rotation of said cam which in turn moves the wrap spring back to a disengaged condition. Thus the rotating power roll 40 also acts to assist in maintaining this clutch wrap spring in its .disengaged or opened condition.

.In the operation of the above described power operated ribbon feed reversing control mechanism when the control lever 25 is pivotally displaced in a counter clockwise direction, FIGURE 1, due to the fact that most of the priting ribbon has been wound onto the spool 11, the integral bent off ear 70 will swing out from under the radially disposed end 67 of the wrap spring 64 thereby permitting the latter to grip the clockwise rotating power roll shaft 45 so as to temporarily rotatably couple the power roll and the cam. 63. During the resultant 360 degree rotational movement of cam 63 the helical camming surface 62 will displace the depending bail leg 61 and hence shaft 21 to the right, FIGURE 1, against the action of spring 36 until the bevel gears 20 and 23 move out of mesh and gears 17 and 22 move into mesh; the shaft collar and the depending finger 38 of control lever 26 then becoming effective to hold shaft 21 in this axially shifted position as above described. If the oscillatory motion of control lever pallet 72 is relatively slow the wrap spring end 67 may be intercepted by the bent off car 73, however even in this case the drive shaft 21 will have been shifted to its right hand position in that the effective camming surface 62 extends about only a relatively short portion of the periphery of the cam 63. Due to the elongated character of gear 42 the shaft 21 may still be rotatably driven from the power roll after shaft 21 has been shifted to its latched position.

The bevel gears 17 and 22 will remain in engagement until the ensuing intermittent rotary indexing movement of the drive shaft 21 rotates the spool to the extent necessary to collect most of the printing ribbon. When about all of the ribbon has played out from spool 11 the control lever 26 will be actuated thereby removing the detenting effect of finger 3 8 on the collar 37 whereupon shaft 21 is free to axially move to the left under action of spring 36 so as to disengage bevel gears 17' and 22 and re-e'ngage bevel gears 20 and 23. This action will cause the printing ribbon to again be fed back onto the spool 11 during subsequent typing operations.

In accordance with the above described apparatus the printing ribbon is power driven longitudinally back and forth across the printing point by apparatus that is intermittently actuated directly from the typewriter power roll. Likewise this ribbon feed drive apparatus is repeatedly automatically reversed by apparatus which is also power actuated directly from the typewriter power roll. The instant structure has been extensively tested and has been found to be very efi'icient and to have a long life of reliable performance.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration only and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

The invention elaimed is:

1. In a business machine having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be fed longitudinally past the printing zone of the machine, drive means for rotating said spools, shifta'ble control means for said drive means for controlling the effective direction of operation of said drive means whereby said ribbon may be fed in either longitudinal direction, and a continuously rotating power driven member; the improvement comprising a first clutch means for intermittently coupling said power driven member to said drive means so as to incrementally drive said spools in one operative direction, and a second clutch means for coupling said power driven member to said control means so as to power shift said control means and thereby permit the driving of said spools in the other operative direction.

2. In a business machine having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be fed longitudinally past the printing zone of the machine, drive means for rotating said spools, shiftable control means for said drive means for controlling the effective direction of operation of said drive means whereby said ribbon may be fed in either longitudinal direction, and a continuously rotating power driven member, and a bail assembly cyclically operable during each printing operation of the machine; the improvement comprising clutch means operatively connected between said continuously rotating member and said drive means, and clutch control means operable in response to the actuation of said ball assembly for engaging said clutch means for a predetermined period, said clutch means including a wrap spring and said clutch. control means including an escapement device which controls one end of said wrap spring.

3. In a business machine having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be fed longitudinally past the printing zone of the machine, drive means for rotating said spools, shiftable control means for said drive means for controlling the effective direction of operation of said drive means whereby said ribbon may be fed in either longitudinal direction, and a continuously rotating power driven member, and a ribbon feed sensing device normally operated when the direction of feed of said ribbon requires reversal; the improvement comprising a clutch operatively connected between said driven member and said control means, and a clutch control means responsive to the operation of said ribbon feed sensing device for engaging said clutch for a predetermined period so as to power shift said control means.

4. Apparatus as defined in claim 3 wherein said clutch includes a wrap spring, and wherein said clutch control means includes an escapement device which controls one end of said wrap spring. a

5. In a business machine having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be longitudinally fed past the printing zone of the machine, drive means for rotating said spools, shifta'ble control means for said drive means for controlling the effective direction of operation of said drive means so that said ribbon may be fed in either longitudinal direction, a ribbon feed sensing device normally operated when the direction of feed of said ribbon requires reversal, a bail assembly cyclically operable during each printing operation of the machine, and a continuously rotating power driven member; the improvement comprising a first clutch means connected between said power driven member and said drive means and operative in response to the cyclic operation of said bail assembly to intermittently feed said printing ribbon in one longitudinal direction, and a second clutch means connected between said power driven member and said control means and operative in response to the operation of said ribbon feed sensing device so as to power shift said control means and thereby reverse the direction of longitudinal feed of said printing ribbon.

6. Apparatus as defined by claim 5 wherein said first clutch means includes a wrap spring one end of which is controlled by said cyclic operation of said bail assembly, and wherein said second clutch means includes a wrap spring, one end of which is controlled by the operation of said ribbon feed sensing device.

7. In a typewriter having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be fed longitudinally past the printing point of the machine, drive means for rotating said spools, control means for said drive means for controlling the effective direction of operation of said drive means so that said ribbon may be fed in either longitudinal direction, a universal bail assembly cyclically operable in response to the successive printing operations of the typewriter, a ribbon feed sensing device normally operated when the direction of longitudinal feed of said ribbon requires reversal, and a continuously driven power roll; the improvement comprising a first clutch means operatively connected between said power roll and said drive means, an escapement mechanism cyclically operated by said universal bail assembly for controlling the engagement of said clutch means and the resultant incremental feeding of said ribbon, and a second clutch means operatively connected between said power roll and said control means and controlled by the operation of said ribbon feed sensing device for power shifting said control means and reversing the direction of the ribbon feed.

8. In a typewriter having a pair of rotatably mounted ribbon spools carrying a printing ribbon that is adapted to be longitudinally fed past the printing pointof the machine, drive means for rotating said spools, shiftable control means for said drive means having normal and shifted operative positions for respectively controlling the effective direction of operation of said drive means whereby said ribbon may be fed in either longitudinal direction, a pair of ribbon feed sensing devices respectively associated with said ribbon spools and each being normally operated when the direction of feed of said ribbon requires reversal, a bail assembly cyclically operable in response to each successive printing operation of the typewriter, and a continuously driven power roll; the improvement comprising clutch means operatively connected between said power roll and said control means, means biasing said control means to a normal position, means controlled by one of said ribbon feed sensing devices for engaging said clutch means so that said control means is displaced to a shifted position, and detent means connected to the other of said ribbon feed sensing devices for releasably retaining-said control means in said shifted position, the subsequent operation of said other ribbon feed sensing device effectively releasing said control means for movement back to its said normal position under the action of said biasing means.

9. Apparatus as defined by claim 8 additionally comprising a second clutch means operatively connected between said power roll and said drive means, and clutch control means cyclically operated in response to the operation of said bail assembly for controlling the operation of said second clutch means.

10. Apparatus as defined by claim 9 wherein each of said clutch means includes a wrap spring, and wherein said clutch control means for said second clutch means includes an escapement device.

11. Apparatus in accordance with claim 1 wherein said shiftablc control means includes a shift arm and said second clutch means includes a driven element provided with a cam adapted to engage said arm when said element is driven upon engagement of said second clutch thereby to shift said control means.

12. Apparatus in accordance with claim 1 wherein said shiftable control means includes a shift arm and said second clutch means includes a driven element provided with a cam adapted to engage said arm when said element is driven upon engagement of said second clutch thereby to shift said control means, and detent means operatively associated with said shiftable means to hold said shiftable means in one of its shifted positions.

13. Apparatus in accordance with claim 1 wherein said shiftable control means includes a shift arm and said second clutch means includes a driven element provided with a cam'adapted to engage said arm when said element is driven upon engagement of said second clutch thereby to shift said control means, and detent means operatively associated with said shiftable means to hold said shiftable means in one of its shifted positions, and ribbon spool operated means for releasing said detent means from its holding position thereby to permit shifting of said shiftable means to its other shifted position.

14. Apparatus in accordance with claim 1 including means operated by one of said ribbon spools for effecting engagement of said second clutch means when the ribbon is substantially unwound from said one spool.

Norton et a1 Aug. 28, 1951 Dodge Nov. 4, 1952 

